Featured Research

Pesticides increase risk for Parkinson's disease: Certain people may be more susceptible

Date:

February 3, 2014

Source:

University of California, Los Angeles (UCLA), Health Sciences

Summary:

Previous studies have shown the certain pesticides can increase the risk for developing Parkinson’s disease. Now, researchers have now found that the strength of that risk depends on an individual’s genetic makeup, which in the most pesticide-exposed populations could increase the chances of developing the debilitating disease by two- to six-fold.

Share This

Previous studies have shown the certain pesticides can increase the risk for developing Parkinson's disease. Now, UCLA researchers have now found that the strength of that risk depends on an individual's genetic makeup, which in the most pesticide-exposed populations could increase the chances of developing the debilitating disease by two- to six-fold.

Related Articles

In a previous study published January 2013 in the Proceedings of the National Academy of Sciences, the UCLA research team discovered a link between Parkinson's and the pesticide benomyl, a fungicide that has been banned by the U.S. Environmental Protection Agency. That study found that benomyl inhibited an enzyme called aldehyde dehydrogenase (ALDH), which converts aldehydes highly toxic to dopamine cells into less toxic agents, and therefore contributed to the development of Parkinson's.

In this study, UCLA researchers tested a number of other pesticides and found 11 that also inhibit ALDH and increase the risk of Parkinson's, and at much lower levels than those at which they are currently being used, said study lead author Jeff Bronstein, a professor of neurology and director of movement disorders at UCLA.

Bronstein said the team also found that people with a common genetic variant of the ALDH2 gene are particularly sensitive to the effects of ALDH-inhibiting pesticides, and were two to six times more likely to develop Parkinson's than those without the variant when exposed to these pesticides.

The results of the epidemiological study appear Feb. 5, 2014 in the online issue of Neurology, the medical journal of the American Academy of Neurology.

"We were very surprised that so many pesticides inhibited ALDH and at quite low concentrations, concentrations that were way below what was needed for the pesticides to do their job," Bronstein said. "These pesticides are pretty ubiquitous, and can be found on our food supply and are used in parks and golf courses and in pest control inside buildings and homes. So this significantly broadens the number of people at risk."

The study compared 360 patients with Parkinson's in three agriculture heavy Central California counties to 816 people from the same area who did not have Parkinson's. Researchers focused their analyses on individuals with ambient exposures to pesticides at work and at home, using information from the California Department of Pesticide Regulation.

In the previous PNAS study, Bronstein and his team determined the mechanism that leads to increased risk. Exposure to pesticides starts a cascade of cellular events, preventing ALDH from keeping a lid on DOPAL, a toxin that naturally occurs in the brain. When ALDH does not detoxify DOPAL sufficiently, it accumulates, damages neurons and increases an individual's risk of developing Parkinson's.

"ALDH inhibition appears to be an important mechanism by which these environmental toxins contribute to Parkinson's pathogenesis, especially in genetically vulnerable individuals," said study author Beate Ritz, a professor of epidemiology at the Fielding School of Public Health at UCLA. "This suggests several potential interventions to reduce Parkinson's occurrence or to slow its progression."

In this study, the research team developed a lab test to determine which pesticides inhibited ALDH. Then the researchers found that those participants in the epidemiologic study with a genetic variant in the ALDH gene were at increased risk of Parkinson's when exposed to these pesticides. Just having the variant alone, however, did not increase risk of the disease, Bronstein said.

"This report provides evidence for the relevance of ALDH inhibition in Parkinson's disease pathogenesis, identifies pesticides that should be avoided to reduce the risk of developing Parkinson's disease and suggests that therapies modulating ALDH enzyme activity or otherwise eliminating toxic aldehydes should be developed and tested to potentially reduce Parkinson's disease occurrence or slow its progression particularly for patients exposed to pesticides," the study states.

The study was funded in part by the National Institute of Environmental Health Sciences (P01ES016732, R01ES010544, 5R21ES16446-2 and U54ES012078), the National Institute of Neurological Disorders and Stroke (NS038367), the Veterans Administration Healthcare System, the Michael J. Fox Foundation, the Levine Foundation, the Parkinson Alliance, the National Defense Science and Engineering Graduate Fellowship and the Ruth L. Kirschstein Institutional National Research Service Award in Molecular Toxicology (T32ES015457).

University of California, Los Angeles (UCLA), Health Sciences. "Pesticides increase risk for Parkinson's disease: Certain people may be more susceptible." ScienceDaily. ScienceDaily, 3 February 2014. <www.sciencedaily.com/releases/2014/02/140203163428.htm>.

University of California, Los Angeles (UCLA), Health Sciences. (2014, February 3). Pesticides increase risk for Parkinson's disease: Certain people may be more susceptible. ScienceDaily. Retrieved March 31, 2015 from www.sciencedaily.com/releases/2014/02/140203163428.htm

University of California, Los Angeles (UCLA), Health Sciences. "Pesticides increase risk for Parkinson's disease: Certain people may be more susceptible." ScienceDaily. www.sciencedaily.com/releases/2014/02/140203163428.htm (accessed March 31, 2015).

Featured Research

Mar. 31, 2015  Researchers have illuminated an important distinction between mice and humans: how human livers heal. The difference centers on a protein called PPAR alpha which activates liver ... full story

Mar. 31, 2015  Researchers have recorded the first direct observations of the micro-scale mechanisms behind the ability of skin to resist tearing. The results could be applied to the improvement of artificial skin, ... full story

Mar. 31, 2015  Fewer than half of the physicians trained in the United States in 2013 received formal education or training on the subject of exercise, according to new research. "There are immense medical benefits ... full story

Mar. 31, 2015  Memory and as well as connections between brain cells were restored in mice with a model of Alzheimer's given an experimental cancer drug, researchers report. "With this treatment, cells under ... full story

Mar. 31, 2015  Increasing state alcohol taxes could prevent thousands of deaths a year from car crashes, say researchers, who found alcohol-related motor vehicle crashes decreased after taxes on beer, wine and ... full story

Mar. 31, 2015  Alcoholism takes a toll on every aspect of a person's life, including skin problems. Now, a new research report helps explain why this happens and what might be done to address it. "The clinical ... full story

Mar. 31, 2015  A new population of 'memory' immune cells has been discovered by scientists, throwing light on what the body does when it sees a microbe for the second time. This insight, and others like it, will ... full story

Mar. 31, 2015  Coronary heart disease and stroke, two of the leading causes of death in the United States, are diseases associated with heightened platelet reactivity. A new study in humans suggests an underlying ... full story

Mar. 31, 2015  A new study had researchers seeking answers to why the therapeutic benefit afforded by SSRIs was so limited in children and teenagers. If researchers can uncover the biological mechanisms preventing ... full story

Featured Videos

Solitair Device Aims to Takes Guesswork out of Sun Safety

Reuters - Innovations Video Online (Mar. 31, 2015)  The Solitair device aims to take the confusion out of how much sunlight we should expose our skin to. Small enough to be worn as a tie or hair clip, it monitors the user&apos;s sun exposure by taking into account their skin pigment, location and schedule. Matthew Stock reports.
Video provided by Reuters

Soda, Salt and Sugar: The Next Generation of Taxes

Washington Post (Mar. 30, 2015)  Denisa Livingston, a health advocate for the Dinι Community Advocacy Alliance, and the Post&apos;s Abby Phillip discuss efforts around the country to make unhealthy food choices hurt your wallet as much as your waistline.
Video provided by Washington Post

S. Leone in New Anti-Ebola Lockdown

AFP (Mar. 28, 2015)  Sierra Leone imposed a three-day nationwide lockdown Friday for the second time in six months in a bid to prevent a resurgence of the deadly Ebola virus. Duration: 01:17
Video provided by AFP

Related Stories

May 27, 2013  A large analysis of more than 100 studies from around the world shows that exposure to pesticides, or bug and weed killers, and solvents is likely associated with a higher risk of developing ... full story

Nov. 12, 2012  A new study shows that people who have had a head injury and have lived or worked near areas where the pesticide paraquat was used may be three times more likely to develop Parkinson’s ... full story

May 26, 2011  Researchers have found that exposure to certain pesticides increased the risk of Parkinson's disease (PD) by three-fold, for non-farm workers who simply lived near fields being sprayed. Further, ... full story

Feb. 14, 2011  New research shows a link between use of two pesticides, rotenone and paraquat, and Parkinson's disease. People who used either pesticide developed Parkinson's disease approximately 2.5 ... full story

June 14, 2010  Genetic mutations and workplace exposure to some insecticides together appear to be associated with an increased risk for Parkinson's disease among men, according to a new ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.